A common disadvantage of conventional portable devices, such as mobile telephones and personal digital assistants (PDA), is that they often include small display screens. Small display screens make it difficult for users to view and navigate large data files. For instance, when viewing a web page on a PDA with a small display screen, the user can only view a very limited portion of the web page at a time. The user typically must repeatedly scroll vertically and horizontally to view the entire page.
In addition, known devices use cumbersome navigational and input mechanisms. For instance, on a typical PDA, a user must use a stylus to touch a small scroll bar displayed on the already small touch-sensitive display screen in order to navigate a document. Interacting with the small scroll bar requires very fine motor skills and is often difficult for many users. Some of these devices (e.g., Palm) provide a soft keyboard that allows a user to enter data by tapping on tiny keys on a keyboard representation on the display.
Known mobile telephones have similar disadvantages. The user must typically use buttons that act as horizontal and/or vertical scroll buttons. However, the use of buttons for scrolling does not allow a user to accurately select a position in a document except at finite intervals. While this may be acceptable when navigating documents with preexisting finite scroll intervals (such as lines in a text document), this is not acceptable when navigating a document that does not contain finite scroll intervals (e.g., a map).
Another common disadvantage with mobile telephones is that the speaker takes up some of the limited amount of external space available on the device. If the speaker is placed on the front of the device with the display screen, then the display screen is smaller than it otherwise could be without the speaker on the same face of the device. If the speaker is placed on the back of the device, then the back of the device has less room for other any input device that is also placed on the back of the device. One known solution to these problems is to add an external device that includes the speaker. For example, Handspring® PDAs allow a user to attach an external mobile telephone Springboard® module (VisorPhone®) that includes the speaker through which sound is played. However, this solution requires the addition of new hardware (i.e., the Springboard module) to the underlying PDA.
Thus, it would be an advancement in the art to provide a portable device that is optimized for viewing data on its display screen, allowing a user to view a larger portion of a data file than previous solutions while maintaining a small form factor and user-friendly input and navigational mechanisms. It would be a further advancement in the art to provide a portable device in which the speaker does not consume external space beyond that of other input and output devices on the portable device, without requiring the addition of new hardware.